Sewing machine



Dec. 2s, 1937. l 'E UTZ Y 1 2,103,478

' SEWING MACHINE Filed June 25, 1955 5 sheets-sheer 1 1 l' 11 i i m @QTm qu I m m 1 H I w FM l v i1 'E im i WITNESSES: I INVENTOR:

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WQ. M v l I JA TTORNEYS.

F. LUTZ SEWING MACHINE Dec'. 2s, 1937.

Filed June 25, 1935 4 5 Sheets-Sheet 4 u INVENTOR: 'raric L11/E5ATTORNEYS WI TNESSES:l y@

Dec. 2s, 193:1.v F, UTZ 2,103,478

SEWING MACHINE Filed June 25, '1935 5 sheets-sheet 5 Vam FRA

WITNESSES- f 'Patented De.2s,1937

SEWING MACHINE lFrederick Lutz, Stuttgart, Germany, assigner to EsPATENT ori-ice Union Special Maschinenfabrik, G. m. b. yH.,

Stuttgart, Germany 'application June 25, isaspseriai No. 28,314 A 1sclaims. (ci. 11a- 162) 'Ihis invention relates to sewing machines,particularly to sewing machines` for forming overedge seams, includingboth plain and scalloped or, 'shell stitch seams, either from one orfrom several threads." t

My invention sfdirected toward simplifying and structurally refining'machines of the kind referred to with a .view toward making possibletheir operation at higher speeds than feasible' heretofore, and therebyattaining a correspondingly increased outputfrom them. These 'advantagesI secure in part asherein fter set forth, through provision of stltchforming mechanism wherein threeinstrumentalities cooperate to performall the necessary functions for hich four elements were requiredheretofore. ese instrumentalities'include a reciprocating needle, anon-thread'carrying 'hook loopr to draw loops of the needlethreadfbelowthe throat plate of the machine, and a latch looper adaptedto engage the needle thread above the throat plate and to draw loops ofsaid thread around the edge of the fabric and through previously formedloops, `withincidental casting of such loops from its Ig5 shank and thento' take the loops from the hook looper before re-engaging the needlethread above the throat plate in successive repetitions of the stitchforming cycle.' In addition, my invention 'f providessmoothly-operating. dynamically-balanced parts for actuating the hookloop- `er and the latch looper in such manner as to .draw only therequired amount of the .needle 35 dispense with`thespecial andcomplicated com-` pensating thread take-ups used in louper-sewinglthread in predetermlning tight seam loops of a definite size. As. aconsequence. I am able to machines of ordinary construction.

Another object of my invention isvto provide for the delivery of anauxiliary thread in such a 4o way that 1t 'will be taken only by thenach moper along the edge of the plain or shell stitch seam produced inthe machine.

Another obect of my invention is to make it 'i possible to vary thetiming of the feed means for adaptation of the sewing machines to thefor mation 4either of plain or shell stitch seams.

50 This I secure, alsoas hereinafter more fully explained, by providingsimple actuating parts for the machine so that they are convenientlyaccessible for the purposes of ready interchange.

Other objects and attendant advantages of this ing been-broken awayv toexpose the mechanism at the interior. Fig. II is a 'view drawn to alarger scale and lshowing the front elevation of the lower portion ofthe machine.

' Fig.' III'is a fragmentary view likewise drawn to a larger scale, andshowing the lower' front portion of the machinein plan with theworksupporting plate removed.'

Fig. IV is a detail sectional view taken as indicated by the arrowsIV-IV in Fig. III and 'showl ing, in part, the means for actuating thelatch louper.- t

Fig. V is a detail sectional view taken as indicated by the arrowsV-V inFig. III, and showing the means for actuating the feed dog of themachine.

Figs. VI-X are fragmentary perspective views showing how the needle andtheyhook and'the latch loopers cooperate in forming a plain overedgeseam with the needle thread alone.

Fig. 2H is a detail sectional view showing how the needle and the twolloopers cooperate in forming'an overedge seam with the needle threadand an auxiliary thread.,

Figs. X11-XV illustrate different forms. of seams capable of beingformed with my improved sewing machine.

' As herein shown, the sewing machine of my invention comprises a mainshaft whichismjournaled in the lower part of the machine, and which isprovided at one end with a pulley 2 for coordination by means of aibelt(not shown) with a suitable source of power.. Mounted on the main shafti is an eccentric 3 whereof the upwardlyextending rod 4 is pivotedto alever 5 by which reciprocating motion is imparted to the needle bar t ofthe machine. A pendant arm l of the lever itis relied upon to actuatethe non-thread carrying hook looper 8 which operates lbeneath the throatplate of the machine, to draw a loop from the needle thread, forpresentation to the latch looper as later on explained, the intermediateconnections including a link 8a, and an os.

cillating arm .8b on a rock shaft 8c which is f obllquely arranged asshown in Fig. IlI so that the hook end of said looper swings at an anglethe feed element and by allocating said parts in 1H) is secured a crankit, which, through a link II and a rocker arm IIa, actuates the latchlooper carrier I2. A yoke I3 affords 'journal support for anobiiquely-disposed oscillating shaft I4 whereto the latch looper carrierI2 is fixed, said yoke being in turn secured to another shaft I5, which,see Fig. II, is located beneath the main shaft I, and oscillatedlaterally through engagement of a fork I 6 thereon with a rotary cam rI1on the main shaft I. vThe latch looper is indicated at I8, and, asshown, has a curved body or shank with a hook end adapted to be closedby a pivoted latch after the manner of a knitting machine needle.Incident to rotation of the main shaft I, the latch looper I8 is 4bodilyosciilated substantially at right angles to the swing of the hook looper8 (see Fig. III) toward and away from the seaming needle by action ofthe rotary cam I1 upon the yoke I3, and concurrently moved up and downthrough inuence of the crank Il upon the arm IIa on the oscillatingshaft I 4 which supports the latch looper carrier I2, these combinedmotions causing the hook end of the latch looper to trace a short arcaround the -edge of the fabric in a manner more clearly set forthhereinafter.

An eccentric I9 on the main yshaft I communicates motion, through a link2l), to a rocker 2i by which the feed bar of the machine is horifzontally reciprocated, said feed bar being moved up and down at the endsof its horizontal strokes in opposite directions by the action of theciri cumferential cam groove 23 of a rotary cam 24 which revolves abouta vertical screw Istud 24a threaded into the base of the machine andwhich is driven by means of a worm gear couple 25, 25 from the mainshaft I, see Figs. III and V. As shown, the cam groove 23h is engaged bya 4stud 21 'at the end of. the lever 28,`which latter is fulcrumed forfree oscillation on the rock shaft I5, and connected with the feed bar22 by means of a link 29. 'I'he feed dog 38 on the bar-22 is thusactuated to intermittently progress the fabric across the work supportof the machine for-`seaming by the needle. Attention is directed to thefact that the gear wheel '26 is located in an interval between the mainshaft I and the feed bar rock shaft 2Ia, and betweenV the feed barl link20 and the feed bar 22,Y where it is conveniently accessible from above,and

further to the fact that the rotary cam 24 isy made separate from thegear wheel 26 and secured thereto by two screws 28a, see Fig. III.'I'his construction permitsiready interchange of the parts when thetiming of the feed mechanism is to be altered in adapting the machinefor scallop or shell stitch seaming as presently described.

As shown in Figs. VI-X the throat plate 3! of the machine provides afixed stitch tongue 35 which is aligned in the direction of feed andover which loops of the needle thread are formed by the hook and latchlooers 8 and I8 in the manner about to be' disclosed.

The operation of the'machine in making a plain overedge seam is asfollows:

By the combined action of the eccentric III lformation of severalstitches.

seam loops of a predetermined size without the need of additional meansto absorb excessive slack occasioned bythe movements of the loopers asin prior art sewing machines. The stitch forming cycle begins as shownin Fig. V'I when the latch looper I8 is in fully advanced positionrelative to the needle with its hook end above the throat plate 34immediately adjacent the path of said needle. As the needle 3| descends,it lays its thread 31 into the hook of the Ilatch looper I8 as shown inFig. VII, while said latch looper, in `moving, downward in closeproximity to the stitch tongue'35 draws a loop 31a of said thread aroundthe edge oi' thefabric and through two previously' formed hook and latchlooper loops 31h and 31e temporarilyheld on said stitch tongue after themanner shown in Fig. VIII. As'` the latch looper I8 completes itsoutward and downward movement, its latch closes over the new loop 31a,with incidental casting `oi the two old loops 31D andy 31e as shown inFig. IX, this occurring just about the time that the needle 3i reachesits lowermost position. As the needle 3l starts its ascent, the' hooklooper 8 engages the needle thread 31 also as shown in Fig. IX, and, inmoving away from the needle, draws a loop 31d angularly crosswise ofthebottom of the stitch tongue 35, while the latch looper."

begins to move upward toward the needle through said loop 31d, therebytaking said loop as shown in Fig. X, the needle in the meanwhileascending to its uppermost position concurrently with the latch looperfor repetition of the stitch forming cycle. With the feed dog 30 timedto function once for each stroke of the needle 3i as ordinarily, a plainoveredge seam such as shownjin Fig. XII is producedas a result of thecooperation of the hook and latch looper 8 and I8 with said needle asabove described. f

By providingv a feed eye 38 on the needle bar 8 of the machine, as shownin Fig. XI, to feedan auxiliary thread 39 so that it may be taken by thelatch looper I8 when the latter moves upward to take the needle yarn31,'it is possible toproduce an overedge seam such as is shown in Fig.XIII having an edge fringe thickened by the additional loops 39a of saidauxiliary thread. In this connection it is to be noted that the hooklooper 8 never engages the auxiliary thread 39; and it is for thisreason that the loops 39a formed from said thread arrange themselvesalong the edge of the stitching.

A rotary cam 2l with a differently formed groove 23, or worm gears 25,26 of a different ratio may be employed to change the timing of the feeddog 30 so as' to shift the fabric after the With use 'of the needlethread 31 only there results a scallop or shell stitch'seam such as isshown in Fig. XIV; while, by using both the threads. 31 and 39 withchanged operation of the feed dog 30, it is possible to form a scallopor shell stitch seam such as is shown in Fig. XV, with the added loops39a of the lauxiliary thread doubled with the edge loops formed from theneedle thread. Due to the ready accessibility of the gearing 25, 26 andthe cam 24, the change from one condition of operation to the other canobviously be accomplished with comparative ease and a minimum loss oftime.

Having thus described my invention, I claim:

1. A sewing machine comprising a reciprocating needle; anon-thread-carrying looper to draw loops from the needle thread at oneside of the fabric being seamed; and a latch looper to draw v 2,103,478N loops from the needle thread at the other side of the fabric, and,after drawing'such loops, to take the loops from the first mentionedlooper.

2. A sewing machine comprising a reciprocating needle; anon-thread-carrying looper to draw loops from the needle thread at oneside of the fabric being seamed; a latch looperlto draw loops from theneedle thread at the other side of the fabric, and, after drawing suchloops, to take the loops from the rst mentioned looper; and means toactuate the two loopers to draw only suiiicient thread for tight seamloops of the desired size.

` 3. Asewing machine comprising a reciprocating needle; a xed stitchtongue; a non-threadcarrying looper to draw loops from the needle threadbeneath the stitch tongue; a latch looper the needle thread above thestitch tongue, and,

.` of the desired size.

. tive beneath the throat plate; means for actuatyafter drawing suchloops, to vtake the loops from the first mentioned looper; means foractuating the first mentioned looper to draw only suillcient thread forseam loops of the desired size; and means for actuating the latch loopersuch that its hook end describes Va short arc around the edge of thestitch tongue likewise for seam loops 5. A sewing machine comp- 'sing areciprocating needle; a-throat plate; a hook looper opera-1 ing the hooklooper to draw loops from the needle thread; a latch looper; andactuating means for moving the latch looper to draw a loop of the needlethread above the fabric, around the fabric 'edge and through a pairofpreviously formed loops thereon with incident casting of said loops, ,A

and then to take the-loop' from the hook looper aforesaid beforereengaging .the needle thread above the throat plate in -initiatinganother stitch forming cycle.

6. A sewing machine 4comprising a reciprocat.

ing needle; a throat plate affording a stitch tongue; a hook` looperoperativeV beneath the throat plate; means for actuating the hook looperto draw loops o f the needle thread under the stitch tongue; a latchlooper; and means for actuating the latch looper so that its hook endtraces an arc angularly tothe direction of feed and in close proximityto the edge of the stitchtongue, and in so moving', engages the needlethread above the throat plate to draw a loop therefrom downward varoundthe edge of the fabric and through previously formed loops on 'itsshank, with vincidental casting of such previous loops, and thereaftertakes the loop from the hook looper before reengaging the needle threadabove the vthroat plate to initiate another stitch forming cycle.

'7. A sewing machine comprising a reciprocating needle; a throat plate;a hook looper operative beneath the throat plate; means for oscillatingthe hook looper to form loops from the needle. thread; a latch looper; acarrier for saidv latch .looper; a laterally oscillating support towhich said latch looper is pivoted with capacity for up and downmovement; and means for oscillating the support and for concurrentlyswinging the latch looper about its pivot axis on thesupport whereby itis caused to draw a vloop from the needle thread above the throat plate,around the edgev of the fabric and through two previously formed loops'thereon with incident casting of. said loops, and then to take the .loopfrom the hook looper aforesaid before re-engaging the needle threadabove the throat plate in initiating another stitch forming cycle.

8. A sewing machine comprising a reciprocatying needle; a throat plate;a hook looper operative beneath the throat' plate; means for oscillatingthe hook looper about an axis oblique to the direction of feed to engagethe needle thread and draw loops therefrom; a latch looper; a' supportfor the latch looper oscillating laterally about an axis aligned inthedirection of feed; an oblique axis on the support whereto the latchlooper is secured with capacity for up and down movement incident tobeing swung ,at substantially right angles to the movement of the hooklooper;

and means for oscillating the support and for concurrently rocking thelatch looper' on its pivot axis so that it is caused to draw a loop fromthe needle thread 'above the throat plate around the edgeof -the'fabricand through two previously formed loops on its shank, with incidentcasting of such loops, and then to take the loop from the hook looperaforesaid before re-engaging e the needle thread above the throat platein initiating another stitch forming cyclesV 9. A sewing machinecomprising a needle bar with a reciprocating needle carrying a seamingthread; an eye on the needle bar for Aguiding an auxiliary thread; athroat plate; a hook looper operative beneath the throat plate; meansfor actuating the hook looper to draw loops from the needle thread belowthe throat plate; a latch looper; and actuating means for moving thelatch looper to concurrently draw loops from the needle and auxiliarythreads above the throat plate| through previously formed loops thereonwith incident casting of the latter loops, and. then forwardly andupwardly to take the loop from the hook looper aforesaid beforere-engaging the needle thread and the auxiliary thread above the foractuating the hook looper to draw loops from Y the needle thread aroundthe bottom of the stitch tongue; a latch looper; and actuating means formoving/the latch looper downwardly and outwardly away from the needleabove the throat plate to draw a loop of the needle thread around thestitch tongue and through a pair of previt ously formed loopsthereonwith incident casting of the latter loops, then forwardly andupwardly to take the loop from the'hook looper aforesaid beforere-engaging the needle thread above the throat plate.

11. A sewing machine comprising a reciprocating needle; a non-threadcarrying looper for drawing loops from the needle thread at one side ofthe fabric being seamed; a latch looper for drawing loops from theneedle thread at the other side of the fabric, and, after drawing such"loops, taking the loops from the rst mentioned looper; and means forfeeding an auxiliary yarn so as to be taken by the latch looper at thesame time that the latter engages the needle thread.

12. In a sewing machine comprising a reciprocating needle, a feed dog,and means for reciproeating the feed dog horizontally; the combinationof a non-thread carrying looper for drawing loops from the needle threadat one side of the fabric -being seamed, a latch looper for drawingloops cating needle, a feed dog, means for reciprocating rocates thefeed dog horizontally; the combina- 'i the feed dog, a rotary shaft, anda rocker actuated by an eccentric on the shaft for reciprocating thefeed dog horizontally; the combination of a non-thread carrying looperfor drawing loops from the needle thread at one side of the fabric beingseamed, a latch looper for drawing loops from the needle thread at theother side of the fabric, and, after drawing such loops taking the loopsfrom the first mentioned looper, means whereby the. two loopers areoperated from the shaft aforesaid, a rotary cam driven by gearing fromthe shaft, and a lever operated by the rotary cam moving the feed doglup and down.

14. In a sewing machine comprising a reciprocating needle, a rotaryshaft, a feed dog, a rocker actuated by an eccentric on the shaft whichreciption of a non-thread carrying looper for drawing the loops from theneedle thread at one side of the fabric being seamed, a latch looper fordrawing loops from the needle thread at the other side of the fabric andafter drawing such loops taking the loops from the first mentionedlooper, connections whereby the two loopers are operated from the`rotaryshaft, a rotary cam on said shaft, a lever operated by the rotary camfor moving the feed dog up and down,-a worm gear to which the rotarycamis detachably secured, and a worm on the main shaft for driving the wormwheel.

15. In a sewing machine, a reciprocating needle, a transverselyreciprocating thread manipulating element cooperating with the needle atone i side of the fabric being sewed, and a transverselyreciprocatinglatch looper cooperating with the needle at the other side of the fabricin the formak tion of stitches.

16. In a sewing machine, a reciprocating needle, a transverselyreciprocating thread manipulating element cooperating with the needle atone side of the fabric being sewed, a transversely-reciprocating'latchlooper cooperating with the needle at the other side of the fabric inthe formation of stitches, and means for advancing the fabric relativeto the needle each time only after several actuations of the needle, thethread manipulating element and the looper to determine formation ofshell stitch effects.

17. A sewing machine comprising a reciprocating needle; a non-threadcarrying looper for drawing loops from they needle thread at one side ofthe fabric being vseamed; a latch looper for drawing loops from theneedle thread at the other side of the fabric, and, after drawing suchloops, taking the loops from the first mentioned looper; means forfeeding an auxiliary yarn so as to be taken by the latch looper at thesame time that the latter engages the needle thread; and means foradvancing the fabric relative to the needle each time only after severalactuations of the needle and the two loopers whereby the formation ofshell stitch effects is determined.

18. In a sewing machine comprising a reciprocating needle, a feed dogand means for horizontally reciprocating said feed dog in synchronismwith the needle; the combination of a non-thread carrying loopercooperating with the needle at one side of the fabric being sewed, alatch looper to cooperate with the needle at the opposite side of thefabric, and means for imparting lift movements to the feed dog such thatthe fabric is advanced each time only after several actuations of theneedle and the two loopers whereby the formation of shell stitch effectsis determined.

FREDERICK LU'IZ.

